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Research on middle-temperature acidic electroless nickel plating on steel
Choosing suitable complexing agent and accelerant is the key to middle-temperature acidic electroless nickel plating.
Further researches on complexing agent and accelerant of middle-temperature acidic electroless nickel plating on steel show that the optimal compound complexing agent is a mixture of lactic acid and a mineral acid with addition amount of 20 mL/L, and optimal accelerant is an organic acid with addition amount of 6 g/L. The influences of pH value and temperature on the deposition rate were studied. The optimal range of pH value and temperature are 4.8～5.2 and 65～90 ℃ respectively. The MTO experiment results demonstrate that different addition amounts of additive' concentrated solution have considerable effects on bath life span and deposit performance. When the addition amount of additive' concentrated solution is 15% by weight, the bath has a life span of over 10 MTO and stability constant of over 97%, the deposition rate is high, and the deposits have hardness of 480 HV as plated and (1 346) HV after heat treatment, and have anti-nitric acid tarnish time of over 70 s, phosphorus weight percent of 11%～12%, and even and bright appearance. SEM photos show dense and uniform micro-structure of deposit surface.
Published: December 25, 2005
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